Machu Picchu represents the culmination of Inca public works building standards and technology, as well as 4,000 years of Andean community development. This landmark is the most well known archaeological site in South America and serves as a destination site for world travelers. It was a royal estate for Emperor Pachacuti.
Spanish

YearAdded:
Image Credit: Courtesy Flickr/Chang'r (CC BY-ND 2.0)Image Caption: Machu PicchuEra_date_from: 1460
2006

The fort was constructed of coquina rock. Unique to Florida, the rock consists of millions of seashells cemented together. It proved highly durable and easily absorbed the force of many cannon balls.
The Castillo de San Marcos was the first permanent European settlement in the continental United States. Originally an outpost of the Spanish Empire, it is the oldest major engineered structure existing in America.
YearAdded:
Image Credit: Courtesy Flickr/inazakira (CC BY-SA 2.0)Image Caption: Castillo de San MarcosEra_date_from: 1672
1975